Curved Precast Concrete Bridges

Precast, prestressed concrete has been used extensively in the nation’s highway bridges beginning in 1949. The

vigorous construction of the interstate highway system beginning in the 1950s, resulted in the creation of new

products and the subsequent development of higher performance materials and methods. Today, precast,

prestressed concrete is recognized as the most durable and cost-effective bridge construction solution for the

span ranges in which it is applicable.

Girders are manufactured in sophisticated, PCI-certified plants on permanent long-line casting beds in strong,

accurate steel forms. The plants use high-strength, high-performance concrete that assures rapid fabrication

cycles and excellent long-term performance. They use pretensioning to prestress the girders.

For more than 60 years, straight girders have been used to economically construct curved bridges. The girders

form chords under the curved, cast-in-place concrete decks. Innovation has led to girder segments being spliced

within spans to frame bridges with shorter radius curvatures.

Throughout the history of the industry, unique projects have been constructed that demonstrate the viability of

casting curved precast concrete girders. Several of these have been used on transit guideways. Some have

necessitated shipping curved girders over extensive distances. All have required stringent fabrication and

construction tolerances.

A project completed in 1983 in Philadelphia, Pa., and one in 1995 in Denver, Colo., began the evolution of thinking

about using curved girders for highway bridges. Numerous projects have been built since 2005. Many of these

projects are described in this report. Analysis and design concepts are discussed. Construction issues are

presented. References are provided for further reading.

In 2006, the PCI Bridge Committee recognized the need to gather and disseminate information about curved

precast concrete bridges and especially curved girder technology. The information was needed by practitioners

throughout the industry including designers, manufacturers, and the owner agencies. In that year, they

established the PCI Curved Precast Bridges Subcommittee. Membership comprised a select group of industry

stakeholders and consulting membership added a larger number of contributors. The subcommittee has been

meeting in formal sessions at least twice each year since 2006.

PCI is recognized as the organization that develops and maintains the body of knowledge of the precast and

precast, prestressed concrete industry. Since 1954, PCI has researched, refined, and published the technology of

this industry. PCI developed comprehensive guidelines and standards for drafting, design, production, quality

control, and installation of precast concrete. It administers the industry’s first and most comprehensive family of

certification programs for personal, production, and erection of precast concrete―all of which are predicated on a

continuous process of quality improvement.